You've probably seen the pictures of bioluminescent bays all over Instagram. They're the ones where the water appears to be glowing. The effect comes from the millions of microorganisms (called dinoflagellates) living in the bay. Each dinoflagellate glows for just an instant every 24 hours or so. There are only five bioluminescent bays in the world, and some are close enough that you can easily add them on your travel bucket list. Here they are in order of brightness.

La Parguera — Lajas, Puerto Rico

La Parguera at sunset with boats floating on the water
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As if you didn't have enough reasons to visit a U.S. territory, now you can add bioluminescent bays to your list. La Parguera is in the southwest corner of Puerto Rico. It sits near the quiet fishing village of Lajas. The bay is part of La Parguera Nature Reserve, which is home to some of the most biologically diverse ecosystems you'll find on the island.

La Parguera is the only bioluminescent bay in Puerto Rico that allows motorboats. However, the pollution created by the motorboats has disturbed the ecosystem. The bioluminescence isn't as bright as it was in the past. Many are concerned that the bioluminescence is going to disappear completely because the bay is not properly protected. So, if you want to see La Parguera while it's still glowing, you should book your trip soon.

Kayaking is the best way to see the magic at night as the dinoflagellates become active. You can also take a glass-bottom boat if you don't want to deal with paddling through mangroves.

Laguna Grande — Fajardo, Puerto Rico

Beach with mountains in the background
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Laguna Grande in Fajardo, Puerto Rico, technically isn't a bay. It's actually a lagoon, thanks to the long and narrow canal that leads to the bioluminescent water. Out of Puerto Rico's three bioluminescent "bays," Laguna Grande is the most popular for tourists because it's the closest to San Juan. It's part of the Las Cabezas Natural Reserves, which is a 316-acre plot of land that's home to some of the most diverse ecosystems you can find in the world.

Along with the bioluminescent lagoon Laguna Grande, Las Cabezas Natural Reserves is home to coral reefs, mangroves, dry forests, and sandy and rocky beaches. Visitors can take tours of the water via a kayak or electric boat and put their hands in the lagoon. Swimming is not allowed. You can also walk around the lagoon to witness the magic without stepping foot on a boat. When you kayak, you have to paddle through mangroves, which can get tricky after sunset. If you're not a strong paddler, you may want to consider taking the electric boat instead so you can sit back and enjoy the view.

Halong Bay — Vietnam

Halong Bay in Vietnam
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Halong Bay in Vietnam is the bioluminescent bay that's farthest away from the U.S. on our list. It was designated as a UNESCO World Heritage Site in 1994. Today, it's one of the most popular tourist destinations in the country. There are 1,600 untouched and uninhabited islands situated within the bay, leaving kayakers and boaters surrounded by pristine and serene natural beauty. It's a water lover's dream come true.

Halong Bay is the large, primary bay, and there are smaller bays available for swimming, kayaking, boating, and touring. Lan Ha Bay in Cat Ba Island is where you'll find the bioluminescence. This bay tends to be off the beaten track and isn't part of a lot of bay tour itineraries. It's also a bit of a journey from the more popular (and populated) Ha Long City. That makes it a pleasant find for anyone who wants to get away from it all and experience the magic of bioluminescence. A kayak or boat tour is the best way to explore the bay, but you can also take a seaplane if you want to get a broader perspective.

Luminous Lagoon — Jamaica

Glowing waters in the Luminous Lagoon
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Located in Falmouth, Jamaica, Luminous Lagoon lives up to its name. Every night, you can find boats full of tourists riding on the lagoon, watching the water below them as it lights up from the millions of dinoflagellates who live there. When the water is disturbed by the boats, the dinoflagellates light up briefly, giving you a glimpse of the world that lives below the water.

Luminous Lagoon is uniquely situated at a point where the Caribbean Sea and the Martha Brae River meet. This means that it has layers of both saltwater and freshwater. The microorganisms glow brightest in water that's warm and shallow, and the lagoon's depths only range from about three to eight feet. This makes it one of the best places in the world to witness the bioluminescent phenomenon.

What makes Luminous Lagoon even more special is that you can get in and swim in the bay at a certain point in your guided tour. Jamaica's a small enough island that it's pretty easy to get to the lagoon no matter where you're staying. It's just 20 minute east of Montego Bay and 45 minutes west of Ocho Rios.

Mosquito Bay — Vieques, Puerto Rico

Photo of water rushing over shoreline at sunset
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Mosquito Bay is internationally recognized as the brightest bioluminescent bay in the world, according to the Guinness Book of World Records. Located on the southern shore of the Puerto Rican island Vieques, this magical bay has seemingly miraculously recovered after it went dark because of Hurricane Maria in 2017. For your best chances of experiencing the full magic of the bioluminescent bay, make plans to visit during the new moon phase.

Like most other bays, swimming is not allowed in Mosquito Bay, because of the disruption it brings to the ecosystem. You can take a kayak tour and put your hand in the water as you paddle along to disrupt the water enough for the bay to glow.

Mosquito Bay glows brighter than other bays in part because it has more dinoflagellates living in it. Somehow, there are more now than there were before Hurricane Maria. It's also further away from city lights than other bays, so you don't have any light pollution corrupting the scenic wonder.